Mechanisms of Decrepitation of Naturally Occurring Spodumene under High-Voltage Pulse Effect and Plasma Treatment
I. Zh. Bunin1, V. A. Chanturia1, E. V. Koporulina1,2, I. A. Khabarova1
1Academician Melnikov Institute of Comprehensive Exploitation of Mineral Resources-IPKON, Russian Academy of Sciences, Moscow, Russia
2Geological Department, Lomonosov Moscow State University, Moscow, Russia
Keywords: Spodumene, low-temperature plasma, dielectric barrier discharge, strong electromagnetic pulses, decrepitation, surface morphology, microhardness, wettability
Abstract
The mechanisms of decrepitation of naturally occurring Kolmozero spodumene under non-thermal treatment by strong nanosecond electromagnetic pulses and low-temperature plasma of microsecond dielectric barrier discharge at atmospheric pressure are analyzed. The analytical scanning electron and confocal laser scanning microscopy, as well as measurements of microhardness, ζ -potential and wetting angle find out that both types of treatment initiate destructuring of minerals without macroscopic heating. It is shown that plasma treatment leads to structural modification of surface layer, i.e. to weakening of crystal bonding, and to softening and increased negative charge of mineral surface. Non-thermal effect of electromagnetic pulses causes destructuring along boundaries of grains and micro-inclusions owing to electrostrictional and shock wave effects, reduces microhardness by 20% and changes wettability of mineral surface. It is found that structural nonuniformity of spodumene is related with its decrepitation in strong electrical fields. The application of high-voltage pulse effects and non-thermal plasma treatment is validated for the energy-efficient preparation of refractory lithium-bearing raw materials.
|
